With the oven rack in the lowest position, preheat oven to 450 degrees.

In a large skillet, heat oil over medium. Stir in onion and carrot - season with salt and fresh ground black pepper. Cook until the vegetables are tender, about 6 to 8 minutes. Stir in garlic and cook until fragrant, about 1 minute. Add sirloin and cook, stirring to crumble meat, until no longer pink, about 5 minutes. Add marinara sauce - bring to a boil, reduce heat to maintain a simmer and cook, stirring occasionally, until the mixture has thickened, about 8 to 10 minutes. Remove from the heat and divide mixture evenly between 4 8-ounce ramekins lightly coated with nonstick spray.

To prepare the topping

In a medium bowl, whisk together flour, cheese, baking powder, salt and rosemary. Pour in melted butter and milk - stir just until combined. Evenly divide topping between the filled ramekins. Set ramekins on a large baking sheet and place into the oven - bake until topping is golden brown and a toothpick placed in the topping comes out clean, about 10 to 12 minutes.